S4 Packet Style

circa 1958-1960

front

back

The S4 style was largely identical to the preceding S3 variant. The principal difference
was the addition in the S4 design of an alphanumeric packet number printed in the solid-color
circle at the upper right of the envelope front:

S3

S4

The reverse of the envelope listed the titles of the three reels in the packet and
advertised other View-Master titles in the same general subject category.

A new alphanumeric packet/reel numbering system was instituted beginning with
the S4 style. The packet number comprised an alphabetic character (A, B, or C)
followed by three digits; reels within a packet were identified with the addition
of a fourth digit (1, 2, or 3). For example, packet B656, Moon Rockets and
Guided Missiles, consisted of reels B6561, B6562, and B6563.